The Precipitator Rapper has been designed to deliver the impulse force required to dislodge accumulated particulates from the collecting plates of an electrostatic precipitation system.
Operation of the rapper is governed by a solid state controller which will precisely set the magnitude and duty cycle of rapping. This reduces considerably the energy consumed as compared to previously available rappers. This savings in operating cost combined with the flexibility, durability and reliability of the rapper, plus its economical price, make this device the logical choice for electrostatic precipitator systems.
The concept and principle of operation of this device is based on simplicity and efficiency. This has led to the development of a product that is easily installed and fully adjustable. Maintenance is negligible.
There are numerous designs for subject rappers which appear to be similar but are not. The unit described herein is the simple lift-drop type which operates as a solenoid to lift a steel hammer of some specified size and allow it to drop. The weight of the hammer, which is dropped a specific distance, creates the foot pounds imparted to the structure and its members, which are to be freed of collected dust. This principle has been known for many dozens of years and no attempt is being made to change it.
All products of this type encompass a coil, a rigid inner dielectric tube, an outer steel or aluminum housing with suitable lower attachment flange and upper enclosing cap. A round steel bar acts as a hammer. The only adjustable feature to current models is permitted by use of threaded rods or spacers which allow the entire rapper to be raised or lowered with respect to the position of the hammer; that is, the hammer is free and rests on the structure it will rap. When the coil is energized, the hammer is lifted. De-energizing the coil allows it (the hammer) to drop. By adjusting the threaded rod, the vertical location of the entire rapper may be changed in order to change location of the coil allowing the lift of the hammer to be adjusted.
In making this adjustment, all components of the rapper change position as a unit except the relative position of the hammer. This creates several problems. First, if the entire assembly is raised, a gap is opened between the top of the precipitator and the rapper. This permits contaminants to enter and heat losses to occur. Second, when the rapper is built as a unit, the coil maintains a fixed position relative to the other components of the rapper. Once the outer shell of the rapper is welded together, it is not practical or feasible to change these relative positions.